iodescription.java

著名的开源仿真软件yale

/*
 *  YALE - Yet Another Learning Environment
 *  Copyright (C) 2002, 2003
 *      Simon Fischer, Ralf Klinkenberg, Ingo Mierswa, 
 *          Katharina Morik, Oliver Ritthoff
 *      Artificial Intelligence Unit
 *      Computer Science Department
 *      University of Dortmund
 *      44221 Dortmund,  Germany
 *  email: [e-mail]
 *  web:   http://yale.cs.uni-dortmund.de/
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License as 
 *  published by the Free Software Foundation; either version 2 of the
 *  License, or (at your option) any later version. 
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 *  USA.
 */
package edu.udo.cs.yale.operator;

import java.util.List;
import java.util.LinkedList;
import java.util.Iterator;

/** This class is a description of the (expected) input and (guaranteed) output classes
 *  of operators. It provides easy default implementations. <br>
 *
 *  @author Simon, Ingo
 *  @version $Id: IODescription.java,v 2.1 2003/04/04 11:59:27 fischer Exp $
 */
public class IODescription {

    public static final int PASS_UNUSED_INPUT_TO_OUTPUT  = 1;
    public static final int DELETE_UNUSED_INPUT          = 2;

    private Class[] inputClasses, outputClasses;
    private int outputBehaviour;
    
    /** Constructs a new IODescription where all input and output classes are
     *  expected exactly once. output is the minimum set of output classes,
     *  the real output classes are determined by the outputBehaviour. 
     *  Both <tt>input</tt> and <tt>ouput</tt> may be null and may contain
     *  a class more than once. */
    public IODescription(Class[] input, Class[] output, int outputBehaviour) {
	this.inputClasses = input;
	this.outputClasses = output;
	if (inputClasses == null) inputClasses = new Class[0];
	if (outputClasses == null) outputClasses = new Class[0];
	this.outputBehaviour = outputBehaviour;
    }

    /** Assumes PASS_UNUSED_INPUT_TO_OUTPUT. */
    public IODescription(Class[] input, Class[] output) {
	this(input, output, PASS_UNUSED_INPUT_TO_OUTPUT);
    }


    /** Returns the classes that are expected as input. */
    public Class[] getInputClasses() {
	return inputClasses;
    }

    /** Returns the output classes dependent on the outputBehaviour
     *  <ul> 
     *  <li><tt>PASS_UNUSED_INPUT_TO_OUTPUT:</tt>output classes are the classes
     *      used in the constructor plus those classes in <tt>input[]</tt> that were
     *      not consumed. Classes are supposed to be consumed by the operator if
     *      they find a matching class in the input classes used in the constructor (which
     *      can be a superclass or interface)
     *  <li><tt>DELETE_UNUSED_INPUT:</tt>output classes are exactly those classes used
     *      in the constructor.
     *  </ul>
     *  In either case the output classes precede the unused input classes. Their order
     *  is conserved.
     **/
    public Class[] getOutputClasses(Class[] input, Operator operator) throws IllegalInputException {
	switch (outputBehaviour) {
	case PASS_UNUSED_INPUT_TO_OUTPUT:
	    List outputList = new LinkedList();
	    for (int i = 0; i < input.length; i++) {
		outputList.add(input[i]);
	    }
	    for (int i = 0; i < inputClasses.length; i++) {
		boolean found = false;
		Iterator j = outputList.iterator();
		while (j.hasNext()) {
		    if (inputClasses[i].isAssignableFrom((Class)j.next())) {
			j.remove();
			found = true;
			break;
		    }
		}
		if (!found) throw new IllegalInputException("Input missing: " + inputClasses[i].getName(), operator);
	    }

	    for (int i = 0; i < outputClasses.length; i++) {
		outputList.add(outputClasses[i]);
	    }	    

	    Class[] outputArray = new Class[outputList.size()];
	    outputList.toArray(outputArray);
	    return outputArray;
	case DELETE_UNUSED_INPUT:
	    return outputClasses;
	}
	return null;
    }

    /** Returns true if oc contains a class which is a superclass of c. */
    public static boolean containsClass(Class c, Class[] oc) {
	for (int i = 0; i < oc.length; i++) {
	    if (c.isAssignableFrom(oc[i])) return true;
	}
	return false;
    }

}